Articles by Joe Marchese

High-pressure switches are designed to shut down a compressor if the system’s high pressure rises above an unsafe level, not allowing the compressor to restart until the pressure returns to a safe level.

One field problem frequently encountered with this type of metering device is that it can become plugged with system debris, causing a restriction. When this happens, the cap tube will typically need to be replaced.

Joe Marchese explains the refrigerant flow control device, which prevents the refrigerant pressure in an evaporator from operating below a minimum value, and discusses how to select the right one for the job.

Any time an oil pressure control shuts down a compressor, the cause of the shutdown must be identified. The tripped control is a warning of another existing problem. Simply resetting the control will not solve the problem.

Not all temperatures sensors are created equal and not all instruments and controllers use the same type of temperature sensors. So the first step in troubleshooting or replacing this type of sensor is to first recognize the type of temperature sensor being used.

The suction line of a refrigeration system is normally insulated with a flexible, closed-cell elastomeric material. Insulating the suction line is done to prevent condensate from developing and dripping off. It also limits the amount of heat added to the refrigerant as it travels back to the compressor.

A popular electrical component used on many control circuits is the step-down transformer. It is the power source for a separate lower-voltage circuit which typically controls the operation of a system.